Quantitative analysis of journals is a way traditional peer review may be augmented to gain a more complete picture of a scholar's impact in his chosen field. Three measures can be used:
number of publications
number of times an author's publications have been cited
the importance of the journal where the article is published, or the Journal Ranking.
Publishing traditions vary between disciplines. Because of this, it is important to compare journals within the same or similar disciplines as much as possible. This will not always be easy as more research becomes interdisciplinary but in order for these journal ranking systems to have meaning the factors measured must compare journals in similar disciplines or subject areas.
Just as you may be aware of predatory journals, seeking to make money from academics eager to be published, fake impact factor sites have appeared on the web. When trying to determine where to publish try as much as possible to use well-known journal ranking resources. Below you will find a list of just some of the sites that are considered unreliable. Many do not share how their metrics are calculated, which is a sign you should be leery.